The invention relates to expandable rooms for habitable structures, especially room structures that are telescopically slideable between retracted and expanded positions for motorized or towed vehicles.
A variety of vehicles are known and used which have a room or a room portion that may be moved from a retracted position while the vehicle is moving over the road and then expanded when the vehicle is stationary in order to provide additional internal space. This type of an arrangement provides adequate space to accommodate users in transit while still keeping the vehicle within governmental regulations that impose width limitations for vehicles on roads and highways. When these vehicles are stationary, they are frequently used for habitation for extended periods of time, and when so used, it is highly desirable to be able to maximize the available living space. This is done in a variety of ways in which the user can move the nested portion of the room out to its expanded position, typically under hydraulic of electrical power.
These expandable room portions usually include a floor, a roof, a side wall, and one or more end walls. In the retracted position, the roof, floor and end walls are typically concealed from exterior view and the room side wall forms a portion of the vehicle side wall. At the same time, the floor of the moveable portion typically rests above the floor of that portion of the room which always remains fixed, and may form a useable portion of the interior flooring during vehicle transit. Since vehicles of this type are used most of the time when stationary with the moveable room in the expanded position, it is highly desirable to eliminate the step up that would be required into the moveable room at the place where the floor of the moveable room joins the floor of the fixed room of the vehicle. The step up to the higher floor of the moveable room from the fixed room is not only inconvenient but also can be somewhat hazardous. In addition, the difference in height between the expanded room and the fixed room restricts movement of furniture within the room and makes it more difficult to create an aesthetically pleasing interior.
The prior art does teach arrangements which allow the floor sections to be at the same height in the expanded position. Many of these structures are complex and so therefore relatively expensive and may be unduly heavy. The additional weight also adversely affects the fuel economy of the vehicle. With the highly competitive market in these recreational vehicles, cost and reliability of operation are important factors.
Some of the prior art structures, although more simplified, have mechanisms that take up space beneath the floor, and when the room is in the retracted position, otherwise available storage space between the floor of the moveable room and the fixed floor is lost
An additional difficulty with the expandable rooms is to provide a reliable system that will not adversely affect the weather sealing that is a necessary component around the opening through which the expandable room moves. In an attempt to provide the advantages of a flush floor when the room is expanded, some prior art systems can damage the weather sealing strips when the expandable room is moved downwardly so that it will be flush when in the fully expanded position. In addition, adequate strength of the supporting structures and proper alignment of the rooms is essential to prevent sagging of the room when in the expanded position and to make certain that no misalignment occurs which will adversely affect the sealing integrity between the moveable room and the fixed portions of the vehicle.
It is therefore an object of the invention to provide an improved expandable room structure for vehicles that is relatively inexpensive to manufacture, reliable in use, and which will provide for a flush floor in the expanded position.